1. Field of the Invention
This invention relates to the field of conveyors and more particularly to the field of pin conveyors with scrapers to contact and clean the inner surfaces of the housing enclosing the conveyed material.
2. Discussion of the Background
Pin conveyors commonly have a plurality of pins mounted in a helical pattern along and about a driven shaft. Frequent applications of such conveyors are to mix, agglomerate, pelletize, agitate, blend and stir particulate/particulate solids or liquid/particulate solids. In operation, the helical pattern of the conveyor serves to advance the material through the housing enclosing it. Such conveyors additionally have desirable application in the handling of thick, sticky, pasty materials such as animal waste which can overpower more conventional screw conveyors having solid blades. As compared to solid blades, the pins can shear through the pasty material while at the same time provide a forwardly directed force due to their helical pattern about the driven shaft.
In handling pasty materials such as animal waste and in particular poultry waste, heat is often added to the material as it is being conveyed through the housing to dry it. However, heating the waste material can aggravate the already existing problem that the material tends to stick or adhere to heated surfaces of the housing. This is particularly the case if the surfaces enclosing the material are metallic. In such applications, any material sticking to the metallic surfaces not only inhibits the efficient transfer of the heat into the material but also impedes the overall conveyance of the material through the housing. Other heating techniques such as applying heated air to the material will also aggravate the sticking problem. Regardless of how or even whether the conveyed pasty material is additionally heated or dried, the sticking problem of the material to the inner surfaces of the conveyor housing must be addressed. Otherwise, the efficient operation of the overall system can be adversely affected.
With this and other problems in mind, the present invention was developed. In it, sleeve members are slidably mounted about the pins of the conveyor and are centrifugally impelled or thrown outwardly to contact and scrape the inner surfaces of the housing. The inner surfaces are then kept cleaner for the more efficient conveyance of the material through the housing as well as the more effective heat transfer to the material as it is being conveyed.